Process of manufacturing cellulose esters



16 organic acids (other than Patented Dec. 6, 1927.

UNITED STATES PATENTOFFICE.

PAUL BERTHON, F LYON, FRANCE, ASSIGNOR TO SOCIETEE DE STEARINERIE 8t SAVONNERIE DE LYON, OF LYON, FRANCE.

PROCESS OF MANUFACTURING CELLULOSE ESTERS.

No Drawing. Application filed February 12, 1924, Serial No. 692,440, and in France July 31, 1923.

In my copending applications Serial Nos. 591,426, filed 29 September 1922, and 623,283. filed 6 March 1923, processes for obtaining soluble cellulosic esters from the higher acids Sand in particular from fatty acids are described.

The present invention has for its object a process of introduction of one or more radicals of the higher fatty acid by esterification 10 not of simple cellulosesbr carbohydrates as in the above mentioned applications but of celluloses or carbo-hydrates which have been previously esterified either by means of min-- eral acids,

the higher fatty acids) for example acetic acid, either by means of derivatives of these acids or by any method.

Broadly the invention consists in the esterification of simple or mixed esters of the cellulose C H O modified or not of which the acid radial or radicals may be either mineral acid residues or organic acid residues (other than higher fatty acid residues) by which mixed cellulosic esters of which one residual acid at least is higher fatty acid are obtained.

The process is carried'out by treating the mineral or organic cellulose esters with fatty acid chlorides in the presence of pyridine and a diluent such for example as benzene, and at a suitable temperature. I

The'pastry mass obtained at the end of the reaction is then precipitated by alcohol and The process is essentially different from all those hitherto known and which consisted in causinga mixture of acid chlorides to act simultaneously oncellulose in the presence 40 of pyridine under which conditions it is impossible to determine in advance what will be the exact constitution of the mixed esters which will be formed and in particular the proportion in which the different organic radicals corresponding to the acid chlorldes used will be really contained in .the ester obtained.

In my process on the contrary the exact composition of the mixed esters prepared can be ascertained in advance for example by starting with nitro-cellulose contam ng a for example nitricacids, or

constituted, by a known tenure of the radical N0 the reaction can be eifected by introducing a determined proportion of a higher fatty acid radical.

For example starting with nitro or acetocellulose containing for each molecule C l-1, 0 one or two nitric or acetic radicals or both, it is possible to obtain by additional esterification mixed diesters or triesters containlng one or two higher fatty acid radicals.

The mixed esters obtained appear in the shape of fibrous filaments which are formed during the precipitation b the alcohol of the mixedester in benzine an toluene.

The1r solubility is more or less modified but they possess in general the valuable property of being soluble. in the aromatic series of hydrocarbons, more particularly benzene.

Their solutions furnish by evaporation transparent and colourless pellicles, the elasticity of which is practically identical and the tenacity greater than that of simple cellulosic esters of the higher fatty acids.

The following is an example of the process:-100 grams of di-nitrocellulose (11.3% about of nitrogen) is dissolved in 200 grams of pyridine and a solution of 300 grams of chloride of lauryl in 300 grams of toluene is added. The mixtureis heated for half an hour to one hour to 40-45 C.

The pasty mass thus obtained is recovered by alcohol in the hot state and it is then purified by dissolution in benzene and reprecipitation of the benzene solution by alcohol.

The yield is from to The laurodinitro-cellubs'e appears in the. form of whitish filaments which are sufficiently resistant and the inflammability of which is considerably less than that of nitro-cellulose. Its solubility is the same as that of simple cellulosic esters of the higher fatty acids.

What I claim as my invention and desire to secure by Letters Patent of the United States is 1. A process for manufacturing mixed cellulose esters soluble in the aromatic series of hydrocarbons, consisting in heating mineral acid cellulose esters together with chlorides of'the higher fatty acids in the presence of pyridine and benzene hydrocarbon, precipitating the mass at the end of the reaction by alcohol and purifying the product obmixture, precipitetin the mass at the end of tained. the reaction by alooho purifying the product 2. Process for manufacturing mixed celluby dissolution in benzene and precipitating 10 lose esters soluble in the aromatic series of the benzene solution by alcohol. 5 hydrocarbons, consisting in dissolving di- In witness whereof I have signed this nitrocellulose in pyridine, addin a solution specification. of chloride of lauryl in toluene, eating the PAUL BERTHON. 

